Emily ate 5 slices of pie. Tiffany ate 3 slices. If Emily ate $\dfrac{5}{9}$ of the pie, what fraction of the pie is remaining?
If 5 slices represent $\dfrac{5}{9}$ of the pie, there must have been a total of 9 slices. $\text{fraction of pie remaining} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 8 slices, which leaves 1 out of 9 slices remaining. There is $\dfrac{1}{9}$ of the pie remaining.